水泥助磨剂研发毕设论文.doc

 四川理工学院毕业论文 研究 学 生: 学 号: 专 业: 班 级:班 指导教师:李富兰 四川理工学院材料与化学工程学院 二〇一年六月 Bachelor of Sichuan University of Science Engineering Name: Wang Chao Student number:11031013611 Supervisor: Li Fu Lan Major: Fine Chemical Material Chemical Engineering Dept. Sichuan University of Science Engineering June 2015牛奶中非法添加硫氰酸钠含量快速检测方法研究 摘 要 本文研究了硫酸铁铵分光光度法测定乳与乳制品中硫氰酸钠的含量方法：样品加三氯乙酸溶液和双氧水溶液置60℃水浴进行蛋白沉淀后，过滤，取滤液加硝酸酸化，再用硫酸铁铵溶液进行显色，在462nm处测定其吸光值，通过绘制的标准曲线，计算出硫氰酸钠含量。实验结果表明：相对于10ml的样品溶液，确定硝酸的最佳用量为10ml，最佳显色时间为30min，本方法的线性范围为080mg/L~16.0mg/L。通过对一系列的标准样品进行精密度实验，计算得出的相对标准偏差为238%。通过对标准样品进行加标回收实验，计算出回收率在948~99.7%之间。以3倍空白标准差作为检出限，通过空白实验得最低检出限为08mg/L，本方法具有操作简便，结果准确，重复性好等优点，实验结果基本符合GB/T 15550-1995《活化乳中乳过氧化物酶体系保存生鲜牛乳实施规范》 关键词：分光光度法；硫酸铁铵；硫氰酸钠；牛奶   Abstract This paper studies the ferric ammonium sulfate spectrophotometry determination of the content of sodium thiocyanate in milk and dairy products. methods: Samples with trichloroacetic acid solution and hydrogen peroxide solution after 60 ℃ water bath for protein precipitation,filter, Take the filtrate with nitric acid acidification, color, can be carried out with ammonium ferric sulfate solution at 462 nm measure its absorbance value, By drawing standard curve to calculate the content of sodium thiocyanate. The experimental results show that: Compared with 10 ml of the sample solution, to determine the optimal dosage of nitrate was 1.0 ml, best chromogenic time for 30 min, this method is linear in the range of 0.80 mg/L ~ 16.0 mg/L. Through a series of standard sample for precision experiment, the calculated relative standard deviation is 2.38%. Through standard addition recovery tests of standard samples, and calculate the recovery rate is between 94.8 ~ 99.7%. Blank in 3 times the standard deviation as the detection limit, through the blank experiment to the minimum detection limit of 0.8 mg/L, this method has si